Tribological characterization of various solid lubricants based copper-free brake friction materials - A comprehensive study

The current work is a comprehensive study dealing with the tribological performance of solid lubricants, namely graphite, tungsten disulfide, molybdenum disulfide, tin disulfide based brake friction materials with other ingredients that were developed as brake pads. The brake pads were analyzed using Industrial standards for physical, mechanical, thermal characteristics. Thermogravimetric analysis was used to study the thermal stability of the varying ingredients and developed pads. Tribological character- ization was done in the pin on disc tribometer with cast iron disc as the counter face following ASTM G 99 where different loads and speeds were considered the testing parameters. Test results showed that molybdenum disulfide based brake pads had less wear rate due to excellent lubrication characteristics, while tungsten disulfide based brake pads had higher friction and thermal stability due to oxide forma- tion. Scanning Electron Microscopy studies revealed plateau formation, pits, cracks and several other characteristics on the tested brake pads surface. (C) 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International conference on Materials and Manufacturing Methods.